1. Field of the Invention
The present invention relates to an apparatus for decolorizing, i.e., fading or "aging," cloth articles, e.g., denim jeans, or for coloring cloth articles. The present invention also relates to a method for operating the apparatus.
2. Description of the Prior Art
A method for decolorizing or aging of denim articles by "stone washing" has been known for some time. Stone washing involves immersing articles of clothing in water or in an aqueous bath containing a base, e.g., a hypochlorite solution, together with small stones or granules of pumice. The pumice stones generally have an average diameter or length on one side of about 1-10 cm. Stone washing produces a clothing article having light-dark shadings at the seams and a uniformly recurring color contrast which is typical of natural wear over the rest of the article.
A method is also known for treating, i.e., decolorizing or fading, cloth articles without immersion in an aqueous bath as in stone washing. This method was also invented by the present applicant and is described in U.S. Pat. No. 4,740,213, the disclosure of which is hereby incorporated by reference. The method involves contacting cloth articles with a coarse, permeable material, e.g., pumice granules, small stones of a technically equivalent material, or granules obtained by compressing paper or the like, the permeable material having been first impregnated with a bleaching agent. The cloth articles may be dry or wet, e.g., damp, when contacted with the impregnated coarse, permeable material, and the contact is generally for a time sufficient to achieve the desired effect.
According to this method, unique faded effects may be achieved on cloth articles, e.g., denim fabrics. For example, cloth articles having random areas of high color contrast due to localized dye removal may be obtained. The random areas may combine a form wisp-like, cloud-like, or smoke-like abstractions which are atypical of normal wear.
In addition to the unique effects which may be achieved, substantial economic advantages may be realized in the treatment of clothing articles by this method. In particular, as compared to conventional stone washing, this method results in significant water, bleach and stone or granule savings. Moreover, the cloth fibers of the articles are subjected to a less severe mechanical action as compared to stone washing and, as a result, articles treated by the method described in U.S. Pat. No. 4,740,213 generally have less fiber degradation.
The present applicant has also disclosed in copending application Ser. No. 151,479, a method for dyeing a textile in a non-uniform manner, the disclosure of which is hereby incorporated by reference. This method involves contacting the textile with rigid, coarse, permeable granules that have been impregnated with a dyestuff. The textile and granules are contacted while in relative random movement with respect to one another for a time sufficient to achieve the desired effect. This method is particularly advantageous because non-uniform, discontinuous, or random, maculated dyeings may be achieved which are not possible by known dyeing methods.
The methods described in U.S. Pat. No. 4,740,213 and U.S. patent application Ser. No. 151,479, are presently accomplished in industrial batch laundry drums with rotating baskets. The cloth articles are placed within the basket with stones or granules impregnated with a bleaching agent or a dyestuff. The duration of the cycle is determined by the type of cloth article and the desired effect. At the end of each treatment cycle, the treated articles must be manually removed from the basket and separated from the granules employed. In the case of cloth articles treated with bleach-impregnated granules, the separated articles are generally fed to a washing operation to neutralize any residual bleach. In the case of contact with dye-impregnated granules, the separated cloth articles may be thermally treated to fix the dyestuff to the article and aqueous washed to remove any excess dyestuff.
Industrial washing machines are limited to the treatment of a batch of a given quantity of cloth articles, usually 5-20 kg. Each time a new cycle is to be run, granules must be impregnated with bleaching agent or dyestuff. At the conclusion of the process, the emptying of the machine and separation of the articles from the granules is an inconvenient and laborious process, posing health and safety risks.